Electronic device with peripheral hybrid antenna

ABSTRACT

An electronic device may have wireless circuitry with antennas. An antenna resonating element arm for an antenna may be formed from peripheral conductive structures running along the edges of a device housing. Elongated conductive members may longitudinally divide openings between the peripheral conductive housing structures and the ground. The elongated conductive members may extend from an internal ground to outer ends of the elongated conductive members that are located adjacent to the gaps. Transmission lines may extend along the elongated conductive members to antenna feeds at the outer ends. The elongated conductive members may form open slots that serve as slot antenna resonating elements for the antenna.

BACKGROUND

This relates generally to electronic devices and more particularly, toelectronic devices with wireless communications circuitry.

Electronic devices often include wireless circuitry with antennas. Forexample, cellular telephones, computers, and other devices often containantennas for supporting wireless communications.

It can be challenging to form electronic device antenna structures withdesired attributes. In some wireless devices, the presence of conductivestructures such as conductive housing structures can influence antennaperformance. Antenna performance may not be satisfactory if the housingstructures are not configured properly and interfere with antennaoperation. Device size can also affect performance. It can be difficultto achieve desired performance levels in a compact device, particularlywhen the compact device has conductive housing structures.

It would therefore be desirable to be able to provide improved wirelesscircuitry for electronic devices such as electronic devices that includeconductive housing structures.

SUMMARY

An electronic device may have wireless circuitry with antennas. Thedevice may have a housing such as a rectangular housing with four edges.The housing may have conductive structures such as peripheral conductivestructures that run along the edges of the housing.

Antennas may be formed from openings between peripheral conductivehousing structures and an internal ground. The openings may extend alongone or more of the edges of the housing. For example, an antenna may beformed using a U-shaped opening that runs along the edges of one of theends of a rectangular device housing.

An antenna resonating element arm for an antenna may be formed from aportion of the peripheral conductive structures that extends betweengaps in the peripheral conductive structures. Elongated conductivemembers may longitudinally divide portions of the U-shaped openingbetween the peripheral conductive housing structures and the ground. Theelongated conductive members may extend from a portion of the ground toouter ends located adjacent to the gaps.

Transmission lines may extend along the elongated conductive members toantenna feeds at the outer ends. The antenna feeds may each have aground terminal coupled to one of the outer ends and a positive terminalcoupled to a portion of the antenna resonating element arm adjacent toone of the gaps. The elongated conductive members may form open slotsthat serve as slot antenna resonating elements for the antenna.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of an illustrative electronic device inaccordance with an embodiment.

FIG. 2 is a schematic diagram of illustrative circuitry in an electronicdevice in accordance with an embodiment.

FIG. 3 is a schematic diagram of illustrative wireless circuitry inaccordance with an embodiment.

FIG. 4 is a schematic diagram of an illustrative inverted-F antenna inaccordance with an embodiment.

FIG. 5 is a schematic diagram of an illustrative slot antenna inaccordance with an embodiment of the present invention.

FIG. 6 is a diagram of illustrative antenna structures and antenna feedsin accordance with an embodiment.

FIG. 7 is a diagram of an illustrative hybrid inverted-F slot antenna inaccordance with an embodiment.

FIG. 8 is a diagram of an illustrative matching circuit and antenna feedconfiguration of the type that may be used in feeding an antenna of thetype shown in FIG. 7 in accordance with an embodiment.

FIG. 9 is a graph in which antenna performance (standing-wave ratio) hasbeen plotted as a function of operating frequency for an illustrativeelectronic device antenna in accordance with an embodiment.

DETAILED DESCRIPTION

Electronic devices such as electronic device 10 of FIG. 1 may beprovided with wireless communications circuitry. The wirelesscommunications circuitry may be used to support wireless communicationsin multiple wireless communications bands.

The wireless communications circuitry may include one more antennas. Theantennas of the wireless communications circuitry can include loopantennas, inverted-F antennas, strip antennas, planar inverted-Fantennas, slot antennas, hybrid antennas that include antenna structuresof more than one type, or other suitable antennas. Conductive structuresfor the antennas may, if desired, be formed from conductive electronicdevice structures.

The conductive electronic device structures may include conductivehousing, structures. The housing structures may include peripheralstructures such as peripheral conductive structures that run around theperiphery of an electronic device. The peripheral conductive structuremay serve as a bezel for a planar structure such as a display, may serveas sidewall structures for a device housing may have portions thatextend upwards from an integral planar rear housing (e.g., to formvertical planar sidewalls or curved sidewalls), and/or may form otherhousing structures.

Gaps may be formed in the peripheral conductive structures that dividethe peripheral conductive structures into peripheral segments. One ormore of the segments may be used in forming one or more antennas forelectronic device 10. Antennas may also be formed using an antennaground plane formed from conductive housing structures such as metalhousing midplate structures and other internal device structures. Rearhousing wall structures may be used in forming antenna structures suchas an antenna ground.

Electronic device 10 may be a portable electronic device or othersuitable electronic device. For example, electronic device 10 may be alaptop computer, a tablet computer, a somewhat smaller device such as awrist-watch device, pendant device, headphone device, earpiece device,or other wearable or miniature device, a handheld device such as acellular telephone, a media player, or other small portable device.Device 10 may also be a television, a set-top box, a desktop computer, acomputer monitor into which a computer has been integrated, or othersuitable electronic equipment.

Device 10 may include a housing such as housing 12. Housing 12, whichmay sometimes be referred to as a case, may be formed of plastic, glassceramics, fiber composites, metal (e.g., stainless steel, aluminum,etc.), other suitable materials, or a combination of these materials. Insome situations parts of housing 12 may be formed from dielectric orother low-conductivity material. In other situations, housing 12 or atleast some of the structures that make up housing 12 may be formed frommetal elements.

Device 10 may if desired, have a display such as display 14. The rearface of housing 12 may have a planar housing wall. The rear housing wallmay be separated into first and second portions by a gap that is filledwith plastic or other dielectric. Conductive structures may electricallycouple the first and second portions together. Display 14 may be mountedon the opposing front face of device 10 from the rear housing wall.Display 14 may be a touch screen that incorporates capacitive touchelectrodes or may be insensitive to touch.

Display 14 may include pixels formed from light-emitting diodes (LEDs)organic LEDs (OLEDs), plasma cells, electrowetting pixelselectrophoretic pixels, liquid crystal display (LCD) components, orother suitable pixel structures. A display cover layer such as a layerof clear glass or plastic May cover the surface of display 14 or theoutermost layer of display 14 may be formed from a color filter layer,thin-film transistor layer or other display layer. Buttons such asbutton 24 may pass through openings in the cover layer. The cover layerMay also have other openings such as an opening, for speaker port 26.

Housing 12 may include peripheral housing structures such as structures16. Structures 16 may run around the periphery of device 10 and display14. In configurations in which device 10 and display 14 have arectangular shape with four edges structures 16 may be implemented usingperipheral housing structures that have a rectangular ring shape withfour corresponding edges (as an example). Peripheral structures 16 orpart of peripheral structures 16 may serve as a bezel for display 14(e.g., a cosmetic trim that surrounds all four sides of display 14and/or that helps hold display 14 to device 10). Peripheral structures16 may also if desired form sidewall structures for device 10 (e.g., byforming a metal band with vertical sidewalls, curved sidewalls, etc.).

Peripheral housing structures 16 may be formed of a conductive materialsuch as metal and may therefore sometimes be referred to as peripheralconductive housing structures, conductive housing structures peripheralmetal structures, or a peripheral conductive housing member (asexamples). Peripheral housing structures 16 may be formed from a metalsuch as stainless steel, aluminum, or other suitable materials. One two,or more than two separate structures may be used in forming peripheralhousing structures 16.

It is not necessary for peripheral housing structures 16 to have auniform cross-section. For example, the top portion of peripheralhousing structures 16 may, if desired, have an inwardly protruding lipthat helps hold display 14 in place. The bottom portion of peripheralhousing structures 16 may also have an enlarged lip (e.g., in the planeof the rear surface of device 10). Peripheral housing structures 16 mayhave substantially straight vertical sidewalls, may have sidewalls thatare curved, or may have other suitable shapes. In some configurations(e.g., when peripheral housing structures 16 serve as a bezel fordisplay 14), peripheral housing structures 16 may run around the lip ofhousing 12 (i.e., peripheral housing structures 16 may cover only theedge of housing 12 that surrounds display 14 and not the rest of thesidewalls of housing 12).

If desired, housing 12 may have a conductive rear surface. For example,housing 12 may be formed from a metal such as stainless steel oraluminum. The rear surface of housing 12 may lie in a plane that isparallel to display 14. In configurations for device 10 in which therear surface of housing 12 is formed from metal, it may be desirable toform parts of peripheral conductive housing structures 1 as integral,portions of the housing structures forming the rear surface of housing12. For example, a rear housing wall of device 10 may be formed from aplanar metal structure and portions of peripheral housing structures 16on the sides of housing 12 may be formed as vertically extendingintegral metal portions of the planar metal structure. Housingstructures such as these may, if desired, be machined from a block ofmetal and/or may include multiple metal pieces that are assembledtogether to form housing 12. The planar rear wall of housing 12 may haveone or more two or more, or three or more portions.

Display 14 may have an array of pixels that form an active area AA thatdisplays images for a user of device 10. An inactive border region suchas inactive area 1A may run along one or more of the peripheral edges ofactive area AA.

Display 14 may include conductive structures such as an array ofcapacitive electrodes for a touch sensor conductive lines for addressingpixels, driver circuits, etc. Housing 12 may include internal conductivestructures such as metal frame members and a planar conductive housingmember (sometimes referred to as a midplate) that spans the walls ofhousing 12 (i.e., a substantially rectangular sheet formed from one ormore parts that is welded or otherwise connected between opposing sidesof member 16). Device 10 may also include conductive structures such asprinted circuit boards, components mounted on printed circuit hoards,and other internal conductive structures. These conductive structures,which may be used in forming a ground plane in device 10, may be locatedin the center of housing 12 and may extend under active area AA ofdisplay 14.

In regions 22 and 20, openings may be formed within the conductivestructures of device 10 (e.g., between peripheral conductive housingstructures 16 and opposing conductive ground structures such asconductive housing midplate or rear housing wall structures, a printedcircuit board, and conductive electrical components in display 14 anddevice 10). These openings, which may sometimes be referred to as gaps,may be filled with air plastic, and other dielectrics and may be used informing slot antenna resonating elements for one or more antennas indevice 10.

Conductive housing structures and other conductive structures in device10 such as a midplate, traces on a printed circuit board, display 14,and conductive electronic components may serve as a ground plane for theantennas in device 10. The openings in regions 20 and 22 may serve asslots in open or closed slot antennas, may serve as a central dielectricregion that is surrounded by a conductive path of materials in a loopantenna, may serve as a space that separates an antenna resonatingelement such as a strip antenna resonating element or an inverted-Fantenna resonating element from the ground plane, may contribute to theperformance of a parasitic antenna resonating element, or may otherwiseserve as part of antenna structures formed in regions 20 and 22. Ifdesired the ground plane that is under active area AA of display 14and/or other metal structures in device 10 may have portions that extendinto parts of the ends of device 10 (e.g., the ground may extend towardsthe dielectric-filled openings in regions 20 and 22), thereby narrowingthe slots in regions 20 and 22. In configurations for device 10 withnarrow U-shaped openings or other openings that run along the edges ofdevice 10, the ground plane of device 10 can be enlarged to accommodateadditional electrical components (integrated circuits, sensors, etc.)

In general, device 10 may include any suitable number of antennas (e.g.,one or more, two or more, three or more, four or more, etc.). Theantennas in device 10 may be located at opposing first and second endsof an elongated device housing (e.g., at ends 20 and 22 of device 10 ofFIG. 1), along one or more edges of a device housing, in the center of adevice housing, in other suitable locations, or in one or more of theselocations. The arrangement of FIG. 1 is merely illustrative.

Portions of peripheral housing structures 16 may be provided withperipheral gap structures. For example, peripheral conductive housingstructures 16 may be provided with one or more gaps such as gaps 18, asshown in FIG. 1. The gaps in peripheral housing structures 16 may befilled with dielectric such as polymer, ceramic, glass, air, otherdielectric materials, or combinations of these materials. Gaps 18 maydivide peripheral housing structures 16 into one or more peripheralconductive segments. There may be, for example two peripheral conductivesegments in peripheral housing structures 16 (e.g., in an arrangementwith two of gaps 18), three peripheral conductive segments (e.g., in anarrangement with three of gaps 18), four peripheral conductive segments(e.g., in an arrangement with four gaps 18, etc.). The segments ofperipheral conductive housing structures 16 that are formed in this waymay form parts of antennas in device 10.

If desired, openings in housing 12 such as grooves that extend partwayor completely through housing 12 may extend across the width of the rearwall of housing 12 and may penetrate through the rear wall of housing 12to divide the rear wall into different portions. These grooves may alsoextend into peripheral housing structures 16 and may form antenna slotsgaps 18, and other structures in device 10. Polymer or other dielectricmay fill these grooves and other housing openings. In some situations,housing openings that form antenna slots and other structure may befilled with a dielectric such as air.

In a typical scenario, device 10 may have upper and lower antennas as anexample). An upper antenna may for example, be formed at the upper endof device 10 in region 22. A lower antenna may for example be formed atthe lower end of device 10 in region 20. The antennas may be usedseparately to cover identical communications bands, overlappingcommunications bands, or separate communications bands. The antennas maybe used to implement an antenna diversity scheme or amultiple-input-multiple-output (MIMO) antenna scheme.

Antennas in device 10 may be used to support any communications bands ofinterest. For example, device 10 may include antenna structures forsupporting local area network communications, voice and data cellulartelephone communications, global positioning system (GPS) communicationsor other satellite navigation system communications, Bluetooth®communications, etc.

A schematic diagram showing illustrative components that may be used indevice 10 of FIG. 1 is shown in FIG. 2. As shown in FIG. 2 device 10 mayinclude control circuitry such as storage and processing circuitry 28.Storage and processing circuitry 28 may include storage such as harddisk drive storage, nonvolatile memory (e.g., flash memory or otherelectrically-programmable-read-only memory configured to form a solidstate drive) volatile memory (e.g., static or dynamicrandom-access-memory), etc. Processing circuitry in storage andprocessing circuitry 28 may be used to control the operation of device10. This processing circuitry may be based on one or moremicroprocessors, microcontrollers, digital signal processors applicationspecific integrated circuits, etc.

Storage and processing circuitry 28 may be used to run software ondevice 10 such a internet browsing applications,voice-over-internet-protocol (VOIP) telephone call applications emailapplications, media playback applications, operating system functions,etc. To support interactions with external equipment, storage andprocessing circuitry 28 may be used in implementing communicationsprotocols. Communications protocols that may be implemented usingstorage and processing circuitry 28 include internet protocols, wirelesslocal area network protocols (e.g., IEEE 802.11 protocols—sometimesreferred to as protocols for other short-range wireless communicationslinks such as the Bluetooth® protocol, cellular telephone protocols,multiple-input and multiple-output (MIMO) protocols, antenna diversityprotocols, etc.

Input-output circuitry 30 may include input-output devices 32.Input-output devices 32 may be used to allow data to be supplied todevice 10 and to allow data to be provided from device 10 to externaldevices. Input-output devices 32 may include use interface devices, dataport devices, and other input-output components. For example,input-output devices 32 may include touch screens, displays withouttouch sensor capabilities, buttons joysticks, scrolling wheels, touchpads, key pads, keyboards, microphones, cameras, buttons, speakers,status indicators, light sources, audio jacks and other audio portcomponents, digital data port devices, light sensors, motion sensorsaccelerometers), capacitance sensors, proximity sensors, fingerprintsensors (e.g., a fingerprint sensor integrated with a button such asbutton 24 of FIG. 1 or a fingerprint sensor that takes the place ofbutton 24), etc.

Input-output circuitry 30 may include wireless communications circuitry34 for communicating wirelessly with external equipment. Wirelesscommunications circuitry 34 may include radio-frequency (RF) transceivercircuitry formed from one or more integrated circuits, power amplifiercircuitry, low-noise input amplifiers, passive RF components, one ormore antennas, transmission lines, and other circuitry for handling RFwireless signals. Wireless signals can also be sent using light (e.g.,using infrared communications).

Wireless communications circuitry 34 may include radio-frequencytransceiver circuitry 90 for handling various radio-frequencycommunications bands. For example, circuitry 34 may include transceivercircuitry 36, 38, and 42. Transceiver circuitry 36 may handle 2.4 GHzand 5 GHz bands for WiFi® (IEEE 802.11) communications and may handlethe 2.4 GHz Bluetooth® communications band. Circuitry 34 may usecellular telephone transceiver circuitry 38 for handling wirelesscommunications in frequency ranges such as a low communications bandfrom 700 to 960 MHz, a low-midband from 1400-1520 MHz, a midband from1710 to 2170 MHz, and a high band from 2300 to 2700 MHz or othercommunications bands between 700 MHz and 2700 MHz or other suitablefrequencies (as examples). Circuitry 38 may handle voice data andnon-voice data. Wireless communications circuitry 34 can includecircuitry for other short-range and long-range wireless links ifdesired. For example, wireless communications circuitry 34 may include60 GHz transceiver circuitry, circuitry for receiving television andradio signals, paging system transceivers, near field communications(NEC) circuitry, etc. Wireless communications circuitry 34 may includeglobal positioning system ((GPS) receiver equipment such as GPS receivercircuitry 42 for receiving GPS signals at 1575 MHz or for handling othersatellite positioning data. In WiFi® and Bluetooth® links and othershort-range wireless links, wireless signals are typically used toconvey data over tens or hundreds of feet. In cellular telephone linksand other long-range links, wireless signals are typically used toconvey data over thousands of feet or miles.

Wireless communications circuitry 34 may include antennas 40. Antennas40 may be formed using any suitable antenna types. For example, antennas40 may include antennas with resonating elements that are formed fromloop antenna structures, patch antenna structures, inverted-F antennastructures, slot antenna structures, planar inverted-F antennastructures, helical antenna structures hybrids of these designs, etc.Different types of antennas May be used for different bands andcombinations of bands. For example, one type of antenna may be used informing a local wireless link antenna and another type of antenna may beused in forming a remote wireless link antenna.

As shown in FIG. 3, transceiver circuitry 90 in wireless circuitry 34may be coupled to antenna structures 40 using paths such as path 92.Wireless circuitry 34 may be coupled to control circuitry 28. Controlcircuitry 28 may be coupled to input-output devices 32. Input-outputdevices 32 may supply output from device 10 and may receive input fromsources that are external to device 10.

To provide antenna structures such as antenna(s) 40 with the ability tocover communications frequencies of interest, antenna(s) 40 may beprovided with circuitry such as filter circuitry (e.g., one or morepassive filters and/or one or more tunable filter circuits). Discretecomponents such as capacitors, inductors, and resistors may beincorporated into the filter circuitry. Capacitive structures, inductivestructures, and resistive structures may also be formed from patternedmetal structures (e.g., part of an antenna). If desired, antennas) 40may be provided with adjustable circuits such as tunable components 102to tune antennas over communications bands of interest. Tunablecomponents 102 may be part of a tunable filter or tunable impedancematching network, may be part of an antenna resonating element, may spana gap between an antenna resonating element and antenna ground, etc.Tunable components 102 may include tunable inductors tunable capacitors,or other tunable components. Tunable components such as these may bebased on switches and networks of fixed components, distributed metalstructures that produce associated distributed capacitances andinductances, variable solid state devices for producing variablecapacitance and inductance values, tunable filters, or other suitabletunable structures. During operation of device 10, control circuitry 28may issue control signals on one or more paths such as path 120 thatadjust inductance values, capacitance values, or other parametersassociated with tunable components 102, thereby tuning antennastructures 40 to cover desired communications bands.

Path 92 may include one or more transmission lines. As an example,signal path 92 of FIG. 3 may be a transmission line having a positivesignal conductor such as line 94 and a ground signal conductor such asline 96. Lines 94 and 96 may form parts of a coaxial cable or amicrostrip transmission line (as examples). A matching network formedfrom components such as inductors, resistors, and capacitors may be usedin matching the impedance of antenna(s) 40 to the impedance oftransmission line 92. Matching network components may be provided asdiscrete components (e.g., surface mount technology components) or maymembered from housing structures, printed circuit hoard structures,traces on plastic supports, etc. Components such as these may also beused in forming filter circuitry in antenna(s) 40 and may be tunableand/or fixed components.

Transmission line 92 may be coupled to antenna feed structuresassociated with antenna structures 40. As an example, antenna structures40 may form an inverted-F antenna a slot antenna, a hybrid inverted-Fslot antenna or other antenna having an antenna feed with a positiveantenna feed terminal such as terminal 98 and a ground antenna feedterminal such as ground antenna feed terminal 100. Positive transmissionline conductor 94 may be coupled to positive antenna feed terminal 98and ground, transmission line conductor 96 may be coupled to groundantenna feed terminal 92. Other types of antenna feed arrangements maybe used if desired. For example, antenna structures 40 may be fed usingmultiple feeds. The illustrative feeding configuration of FIG. 3 ismerely illustrative.

Control circuitry 28 may use an impedance measurement circuit to gatherantenna impedance information. Control circuitry 28 may use informationfrom a proximity sensor (see, e.g., sensors 32 of FIG. 2), receivedsignal strength information, information from one or more antennaimpedance sensors, or other information in determining when antenna 40is being affected by the presence of nearby external objects or isotherwise in need of tuning. In response, control circuitry 28 mayadjust an adjustable inductor or other tunable component 102 to ensurethat antenna 40 operates as desired. Adjustments to component 102 mayalso be made to extend the coverage of antenna 40 (e.g., to coverdesired communications bands that extend over a range of frequencieslarger than antenna 40 would cover without tuning).

FIG. 4 is a diagram of illustrative inverted-F antenna structures thatmay be used in implementing antenna 40 for device 10. Inverted-F antenna40 of FIG. 4 has antenna resonating element 106 and antenna around(ground plane) 104. Antenna resonating element 106 may have a mainresonating element arm such as arm 108. The length of arm 108 and/orportions of arm 108 may be selected so that antenna 40 resonates atdesired operating frequencies. For example, if the length of arm 108 maybe a quarter of a wavelength at a desired operating frequency forantenna 40. Antenna 40 may also exhibit resonances at harmonicfrequencies.

Main resonating element arm 108 may be coupled to around 104 by returnpath 110. An inductor or other component may be interposed in path 110and/or tunable components 102 may be interposed in path 110 and/orcoupled in parallel with path 110 between arm 108 and around 104.

Antenna 40 may be fed using one or more antenna feeds. For example,antenna 40 may be fed using antenna feed 112. Antenna feed 112 mayinclude positive antenna feed terminal 98 and around antenna feedterminal 100 and may run in parallel to return path 110 between arm 108and around 104. Antenna 40 may also be feed by a feed that is located atthe end of arm 108 such as feed 112′. Feed 112′ include positive antennafeed terminal 98′ coupled to arm 108 and round antenna feed 100′ coupledaround 104. If desired, inverted-F antennas such as illustrative antenna40 of FIG. 4 may have more than one resonating arm branch (e.g., tocreate multiple frequency resonances to support operations in multiplecommunications bands) or may have other antenna structures (e.g.,parasitic antenna resonating elements, tunable components to supportantenna tuning, etc.). For example arm 108 may have left and rightbranches that extend outwardly from feed 112 and return path 110.Multiple feeds may be used to feed antennas such as antenna 40.

Antenna 40 may be a hybrid antenna that includes one or more slotantenna resonating elements. As shown in FIG. 5 for example antenna 40may be based on a slot antenna configuration having an opening such asslot 114 that is formed within antenna ground 104. Slot 114 may befilled with air, plastic, and/or other dielectric. The shape of slot 114may be straight or may have one or more bends (i.e., slot 114 may havean elongated shape following a meandering path). The antenna feed forantenna 40 may include positive antenna feed terminal 98 and aroundantenna feed terminal 100. Feed terminals 98 and 100 may for example, belocated on opposing sides of slot 114 (e.g., on opposing long sides).Slot-based antenna resonating elements such as slot antenna resonatingelement 114 of FIG. 5 may give rise to an antenna resonance atfrequencies in which the wavelength of the antenna signals is equal tothe perimeter of the slot. In narrow slots, the resonant frequency of aslot antenna resonating element is associated with signal frequencies atwhich the slot length is equal to a half of as wavelength. Slot antennafrequency response can be tuned using one or more tunable componentssuch as tunable inductors or tunable capacitors. These components mayhave terminals that are coupled to opposing sides of the slot (i.e., thetunable components may bridge the slot). If desired, tunable componentsmay have terminals that are coupled to respective locations along thelength of one of the sides of slot 114. Combinations of thesearrangements may also be used.

Antenna 40 may be a hybrid slot-inverted-F antenna that includesresonating elements of the type shown in both FIG. 4 and FIG. 5. Anillustrative feeding arrangement for a hybrid antenna of this type isshown in FIG. 6. As shown in FIG. 6, hybrid antenna 40 (e.g., a hybridslot-inverted-F antenna) may be fed by transceiver circuitry 90 using afirst feed such as feed F1 and a second feed such as feed F2.Transceiver circuitry 90 may have a first port that is coupled to feedF1 using transmission line 92-1 and a second port that is coupled tofeed F2 using transmission line 92-2. If desired tunable and/or fixedimpedance matching circuits such as matching circuits M1 and M2 may beinterposed in paths 92-1 and 92-2. Additional antenna structures such asantenna 40 (e.g., example elements or other types of antennas) may befed using transceiver circuitry 90 and may help enhance the frequencycoverage of antenna 40. In the example of FIG. 6, antenna 40′ is feed atfeed F3 by coupling a third port of circuitry 90 to antenna 40 usingtransmission line 92-3, but other feeding arrangements may be used ifdesired (e.g., a feeding arrangement in which one of feeds F1 and F2 isused in feeding, element 40). A matching circuit may be interposed inpath 92-3, if desired. Antenna 40′ may be used to provide local wirelesslocal area network coverage at 2.4 and/or 5 GHz while antenna 40 is usedto cover satellite navigation and cellular bands and/or antenna 40′ maybe used to provide coverage in other suitable frequency bands. Ifdesired, additional antenna element 40′ may be omitted or more than oneadditional element such as element 40′ may be included in device 10.Antenna elements such as antenna element 40′ may be located at ends 20and/or 22 or elsewhere in device 10.

An interior view of device 10 showing an illustrative configuration thatmay be used for a dual-feed hybrid antenna is shown in FIG. 7. As shownin FIG. 7, antenna 40 may have an inverted-F antenna resonating elementarm such as arm 108 formed from peripheral conductive structures 16. Arm108 has a first end that is separated from ground plane 104 at gap 18-1and a second end that is separated, from ground plane 104 at gap 18-2.An elongated, opening may separate arm 108 from ground plane 104. Theelongated opening may have a U-shape that runs along three peripheraledges of device 10 or may have other shapes. Antenna arm 108 may have afirst branch such as branch A1 and a second branch such as branch A2.The end of branch A1 at feed F1 may be fed using positive antenna feedterminal 98-1 and ground antenna feed terminal 100-1. The end of branchA2 (i.e., the opposing end of arm 108) at feed F2 may be fed usingpositive antenna feed terminal 98-2 and ground antenna feed terminal100-2.

A central portion of ground plane 104 may extend downwards to formground plane protrusion 104′. Ground plane protrusion 104′ may branchout to form two opposing elongated (strip-shaped) conductive members:conductive member 142-1 and conductive member 142-2. Conductive members142-1 and 142-2 may be formed from machined metal portions of housing12, metal traces on a plastic support structures (e.g., traces patternedusing laser direct structuring techniques in which portions of a plasticsupport are selectively activated by exposure to laser light to promotelocalized metal plating during subsequent electroplating operations)stamped metal foil, wire, or other elongated conductive structures.Structures such as conductive members 142-1 and 142-2 may be supportedby plastic that is molded into the opening between arm 108 and groundplane 104, may be supported on a printed circuit or other substrate, ormay be partly or full) suspended in an between arm 108 and ground plane104.

Radio-frequency transceiver circuitry 90 may be coupled to antenna feedsF1 and 12 at the outer ends of elongated conductive members 142-1 and142-2 using respective transmission lines such as transmission lines92-1 and 92-2. Transmission line 92-1 may include positive signal path94-1 and associated ground signal conductor 96-1. Transmission line 92-2may include positive signal path 94-2 and ground signal path 96-2.Transmission lines 92-1 and 92-1 extend along respective elongatedmembers 142-1 and 142-2 and couple transceiver circuitry 90 torespective feeds F1 and F2. If desired, coaxial cables, flexible printedcircuit cables, or other cables may be used in forming transmissionlines 92-1 and 92-2. For example, a first coaxial cable may run alongmember 142-1 and a second coaxial cable may run along member 142-2. Thecenter conductors of the first and second coaxial cables may formpositive signal paths 94-1 and 94-2. The outer conductors of the firstand second coaxial cables may form ground signal paths 96-1 and 96-2 andmay be shorted to respective ground feed terminals 100-1 and 100-2 atthe ends of members 142-1 and 142-2. If desired, the outer conductors ofthe cables may also be shorted to members 142-1 and 142-2 at one or morepositions along the lengths of members 142-1 and 142-2. Members 142-1and 142-2 may be separate from the ground conductors in transmissionlines 92-1 and 92-1 (i.e., members 142-1 and 142-2 may be separate fromthe outer ground conductor in the first and second coaxial cables) ormembers 142-1 and 142-2 may form some or all of ground signal paths 96-1and 96-2.

The opening between arm 108 and ground 104 may have a shape that runsalong one or more edges of device 10. In the example of FIG. 7, theopening between arm 108 and ground 104 has a U-shape that runs along aportion of the lower left edge of device 10, the bottom edge of device10, and a portion of the lower right edge of device 10. Groundprotrusion 104′ laterally bisects this opening into left and righthalves. The left half of the opening is bisected along its length theleft opening is longitudinally divided) by member 142-1 to form openings130-1A and 130-1B. The right half of the opening is bisected along itslength the right opening is longitudinally divided) by member 142-2 toform openings 130-2A and 130-2B. Openings 130-1A, 130-1B, 130-2A, and130-2B may have the shape of elongated strips and may sometimes bereferred to as slot-shaped openings or slots. Slots such as open slots130-1A and 130-2A may form slot antenna resonating elements thatcontribute to the frequency coverage of antenna 40. The lengths ofopenings 130-1A, 130-1B, 130-2A, and 130-2B may be 1-20 cm, more than 3cm, more than 7 cm, less than 30 cm, less than 20 cm, less than 10 cm,or other suitable lengths. The widths of openings 130-1A, 130-1B,130-2A, and 130-2B 1 may be 0.5-5 mm, may be 1-3 mm, may be more than0.2 mm, may be more than 1 mm, may be less than 3 mm, may be less than 6mm, or may be any other suitable width.

Opening 130-1A may have a closed end at the left side a groundprotrusion 104′ and an opposing open end such as open end 144-1. Opening130-2A may have a closed end at the right side of ground protrusion 104′and an opposing open end such as open end 144-2. Openings 130-1A and130-2A may form first and second respective open-ended slots S1 and S2(sometimes referred to as open slots or open slot resonating elements).In the illustrative configuration of FIG. 7, the open ends of slots S1and S2 are not bridged by positive signal conductors 94-1 and 94-2,because conductors 94-1 and 94-2 run along members 142-1 and 142-2 fromground protrusion 104′ and terminate at respective positive antenna feedterminals 98-1 and 98-2 on the opposing ends of arm 108.

As shown in FIG. 7, components such as inductor 132 and tunable inductor134 (or other tunable component 102) may span the gap (130-1B and/or130-2B) between arm 108 and ground protrusion 104′ of ground 104. Arm108 may have branches such as arm A1 and arm A2. Arm A1 may extendbetween gap 18-1 at feed F1 and components 132 and 134. Arm A2 mayextend between gap 18-2 at feed F2 and components 132 and 134. Slots S1and S2 and arms A1 and A2 form portions of a hybrid inverted-F slotantenna (antenna 40). The lengths of open slots S1 and S2 and thelengths of respective branches (arms) A1 and A2 of resonating element(arm) 108 may form antenna resonance peaks that help ensure that antenna40 will operate it desired communications bands.

FIG. 8 shows how a cable such as coaxial cable 140 may run along member142-2 (the arrangement for member 142-1 may be similar). In the exampleof FIG. 8, cable 140 has a center conductor that forms positivetransmission line path 94-2 and an outer ground conductor that fromground transmission line path 96-2 (i.e., cable 140 of FIG. 8 may formtransmission line 92-2). At feed F2, positive transmission line path94-2 extends across opening 130-2B and is shorted to positive antennafeed terminal 98-2 at the end of arm A2. Impedance matching circuitryfor feed F2 (matching circuit M2) may be formed from electricalcomponents 148 mounted on substrate 146 (as an example). The impedancematching circuitry may be interposed in transmission line 92-2 and maybe coupled to positive feed terminal 98-2 and ground feed terminal 100-2(which is formed by terminating the ground conductor of path 92-2 at theouter end of member 142-2). Structures of the type shown in FIG. 8 maybe used for both feed F2 and feed F1. The impedance matching circuitrymay be fixed or may be tunable (see, e.g., tunable components 102).

FIG. 9 is a graph in which antenna performance (standing-wave ratio SWR)has been plotted as a function of operating frequency f for anillustrative antenna such as antenna 40 of FIG. 7. As shown in FIG. 9,antenna 40 may exhibit resonances in a low band LB, low-middle band LMB,midband MB, and high band HB. Low band LB may extend from 700 MHz to 960MHz, low midband LMB may extend from 1400 MHz to 1520 MHz, midband MBmay extend from 1700 MHz to 2200 MHz, and high band HB may extend from2300 MHz to 2700 MHz (as examples). The resonance at low band LB may beassociated with the length of arm A2. The resonance at low mid-band LMBmay arise from the length of slot S2. The length of arm A1 may give riseto the resonance at mid-band MB. The resonance at high band HB may begenerated from the length of slot. S1. Higher-order resonancesassociated with the length of slot S1 may support an antenna response athigher frequencies such as 5 GHz. If desired, an additional antennastructure such as antenna structure 40′ of FIG. 6 (e.g., a monopole,etc.) may be used in supporting coverage at 5 GHz.

Antennas such as antenna 40 of FIG. 7 may be formed at the lower end ofdevice 10, at the upper end of device 10, at both the upper and lowerends of device 10, or elsewhere in device 10. Different ranges offrequencies may be covered by adjusting components 132 and 134 and/orthe shapes of arms A1 and A2 and slots S1 and S2. Slots S1 and S2 andarms A1 and A2 may be formed along one edge of device 10, along twoedges of device 10, along three edges of device 10 (as shown in FIG. 7),or along four edge of device 10 (as examples). The configuration of FIG.7 is merely illustrative.

The foregoing is merely illustrative and various modifications can bemade by those skilled in the art without departing from the scope andspirit of the described embodiments. The foregoing embodiments may beimplemented individually or in any combination.

What is claimed is:
 1. An electronic device, comprising: a housinghaving peripheral conductive structures; an antenna that has an antennaresonating element arm formed from the peripheral conductive structures,that has an antenna ground that is separated from the antenna resonatingelement arm by an elongated opening that runs along at least one edge ofthe housing, and that has an elongated conductive member within theelongated opening that forms an open slot between the elongatedconductive member and the antenna ground; a first pair of antenna feedterminals and a first transmission line that are coupled to the antennaand that convey radio-frequency signals for the open slot and a firstportion of the antenna resonating element arm; and a second pair ofantenna feed terminals and a second transmission line that are coupledto the antenna and that convey radio-frequency signals for a secondportion of the antenna resonating element arm.
 2. The electronic devicedefined in claim 1 wherein the elongated conductive member has opposingfirst and second ends, the antenna ground has a portion from which thefirst end of the elongated conductive member extends and that forms aclosed end for the open slot, and the open slot has an opposing open endat the second end of the elongated conductive member.
 3. The electronicdevice defined in claim 2 wherein the first pair of antenna feedterminals is located at the second end of the elongated conductivemember.
 4. The electronic device defined in claim 3 wherein theperipheral conductive structures have at least one gap that separatesthe first portion of the antenna resonating element arm from the antennaground and the antenna resonating element arm has an end at the gap. 5.The electronic device defined in claim 4 wherein the first pair ofantenna feed terminals includes a ground antenna feed terminal on thesecond end of the elongated conductive member.
 6. The electronic devicedefined in claim 5 wherein the first pair of antenna feed terminalsincludes a positive antenna feed terminal on the end of the antennaresonating element arm adjacent to the gap.
 7. The electronic devicedefined in claim 6 further comprising: radio-frequency transceivercircuitry, wherein the first transmission line extends along theelongated conductive member between the radio-frequency transceivercircuitry and the first pair of antenna feed terminals.
 8. Theelectronic device defined in claim 7 further comprising at least oneelectrical component that is coupled to the antenna resonating elementarm.
 9. The electronic device defined in claim 8 wherein the elongatedconductive member is separated from the antenna resonating element armby a slot-shaped opening and the electrical component is coupled acrossthe slot-shaped opening.
 10. The electronic device defined in claim 9wherein the electrical component comprises a tunable inductor.
 11. Theelectronic device defined in claim 10 further comprising a fixedinductor that is coupled across the slot-shaped opening.
 12. Theelectronic device defined in claim 11 further comprising: an additionalgap in the peripheral conductive structures, wherein the second portionof the antenna resonating element arm is separated from the antennaground by an additional elongated opening; and an additional elongatedconductive member that longitudinally divides the additional elongatedopening and that forms an additional open slot for the antenna.
 13. Theelectronic device defined in claim 12 wherein the second transmissionline extends along the additional elongated conductive member from thetransceiver circuitry to the second pair of antenna feed terminals, andthe second pair of antenna feed terminals is coupled between theadditional elongated conductive member and an end of the second portionof the antenna resonating element arm that is adjacent to the additionalgap.
 14. An electronic device, comprising: a rectangular housing havingfour edges and peripheral conductive structures that run along at leastsome of the edges; first and second gaps in the peripheral conductivestructures that define an antenna resonating element arm for an antenna;an antenna ground for the antenna; first and second elongated conductivemembers that extend respectively within first and second elongatedopenings that are formed between the antenna ground and the antennaresonating element arm, wherein the first and second elongatedconductive members have respective outer ends; a first antenna feed thatis coupled between the outer end of the first elongated conductivemember and the antenna resonating element arm adjacent to the first gap;and a second antenna feed that is coupled between the outer end of thesecond elongated conductive member and the antenna resonating elementarm adjacent to the second gap.
 15. The electronic device defined inclaim 14 wherein the first and second elongated openings form part of aU-shaped opening that extends around three of the edges.
 16. Theelectronic device defined in claim 15 wherein the three edges include alower edge of the housing and the antenna ground has a protrudingportion adjacent to the lower edge from which the first and secondelongated conductive members extend.
 17. The electronic device definedin claim 16 further comprising: radio-frequency transceiver circuitry;and first and second transmission lines coupled to the radio-frequencytransceiver circuitry and respectively extending along the first andsecond elongated conductive members to the first and second antennafeeds.
 18. The electronic device defined in claim 17 wherein a firstopen slot for the antenna is formed between the first elongatedconductive member and the antenna ground and a second open slot for theantenna is formed between the second elongated conductive member and theantenna ground.
 19. The electronic device defined in claim 18 whereinthe antenna is configured to exhibit a first resonance associated withthe first open slot, a second resonance associated with the second openslot, a third antenna resonance associated with a first portion of theantenna resonating element arm, and a fourth resonance associated with asecond portion of the antenna resonating element arm.
 20. A cellulartelephone, comprising: a housing having peripheral conductive structuresthat are separated from a ground by a U-shaped opening, wherein theground forms part of an antenna; first and second gaps in the peripheralconductive structures at opposing ends of the U-shaped opening, whereina portion of the peripheral conductive structures forms an antennaresonating element arm for the antenna and the first and second gapsform first and second respective ends of the antenna resonating elementarm; and first and second elongated conductive structures thatlongitudinally bisect respective first and second portions of theU-shaped opening, wherein the first and second elongated conductivestructures and the antenna ground form first and second respective openslots that serve as first and second slot antenna resonating elementsfor the antenna; an antenna feed coupled between an end of the firstelongated conductive structure and the antenna resonating element arm;and a transmission line that extends along the first elongatedconductive structure to the antenna feed.
 21. The cellular telephonedefined in claim 20 further comprising: an additional antenna feedcoupled between an end of the second elongated conductive structure andthe antenna resonating element arm; an additional transmission line thatextends along the second elongated conductive member to the secondantenna feed.